1 /* 2 * subscribe.h -- subscription handling for CoAP 3 * see draft-ietf-core-observe-16 4 * 5 * Copyright (C) 2010-2012,2014-2015 Olaf Bergmann <bergmann@tzi.org> 6 * 7 * This file is part of the CoAP library libcoap. Please see README for terms 8 * of use. 9 */ 10 11 12 #ifndef _COAP_SUBSCRIBE_H_ 13 #define _COAP_SUBSCRIBE_H_ 14 15 #include "address.h" 16 #include "coap_io.h" 17 18 /** 19 * @defgroup observe Resource observation 20 * @{ 21 */ 22 23 /** 24 * The value COAP_OBSERVE_ESTABLISH in a GET request indicates a new observe 25 * relationship for (sender address, token) is requested. 26 */ 27 #define COAP_OBSERVE_ESTABLISH 0 28 29 /** 30 * The value COAP_OBSERVE_CANCEL in a GET request indicates that the observe 31 * relationship for (sender address, token) must be cancelled. 32 */ 33 #define COAP_OBSERVE_CANCEL 1 34 35 #ifndef COAP_OBS_MAX_NON 36 /** 37 * Number of notifications that may be sent non-confirmable before a confirmable 38 * message is sent to detect if observers are alive. The maximum allowed value 39 * here is @c 15. 40 */ 41 #define COAP_OBS_MAX_NON 5 42 #endif /* COAP_OBS_MAX_NON */ 43 44 #ifndef COAP_OBS_MAX_FAIL 45 /** 46 * Number of confirmable notifications that may fail (i.e. time out without 47 * being ACKed) before an observer is removed. The maximum value for 48 * COAP_OBS_MAX_FAIL is @c 3. 49 */ 50 #define COAP_OBS_MAX_FAIL 3 51 #endif /* COAP_OBS_MAX_FAIL */ 52 53 /** Subscriber information */ 54 typedef struct coap_subscription_t { 55 struct coap_subscription_t *next; /**< next element in linked list */ 56 coap_endpoint_t local_if; /**< local communication interface */ 57 coap_address_t subscriber; /**< address and port of subscriber */ 58 59 unsigned int non_cnt:4; /**< up to 15 non-confirmable notifies allowed */ 60 unsigned int fail_cnt:2; /**< up to 3 confirmable notifies can fail */ 61 unsigned int dirty:1; /**< set if the notification temporarily could not be 62 * sent (in that case, the resource's partially 63 * dirty flag is set too) */ 64 size_t token_length; /**< actual length of token */ 65 unsigned char token[8]; /**< token used for subscription */ 66 } coap_subscription_t; 67 68 void coap_subscription_init(coap_subscription_t *); 69 70 /** @} */ 71 72 #endif /* _COAP_SUBSCRIBE_H_ */ 73
